Anhydrous candicidin foam compositions

ABSTRACT

Stable, anhydrous, foam compositions containing candicidin useful in the treatment of vaginitis.

United States Patent 1 1 Webb, Jr.

[ Dec. 30, 1975 [54] ANHYDROUS CANDICIDIN FOAM COMPOSITIONS [75] Inventor: Norval Ellsworth Webb, Jr.,

Cincinnati, Ohio [73] Assignee: Richardson-Merrell Inc., Wilton,

Conn.

[22] Filed: Jan. 18, I974 [21] Appl. No.: 434,391

[52] US. Cl 424/45; 424/122 [5]] Int. CI. A61K 9/14 [58] Field of Search 424/45 [56] References Cited UNITED STATES PATENTS 3,092,555 6/1963 Horn 1. 424/45 3,244,589 4/1966 Sunnen 424/45 Primary ExaminerNorman A. Drezin Attorney, Agent, or FirmWilliam J. Stein; Eugene O. Retter; George W. Rauchfuss, Jr.

57 ABSTRACT Stable, anhydrous, foam compositions containing candicidin useful in the treatment of vaginitis.

3 Claims, N0 Drawings ANHYDROUS CANDICIDIN FOAM COMPOSITIONS 1 FIELDOF THEINVENTION This invention relates to novelanhydrous therapeutic compositions of candicidin which can be dispensed as pressurized foams. Q

BACKGROUND OF THE INVENTION Candicidin is a conjugated heptaene antibiotic complex produced by a soil actinomycetes similar to Streptomyces griseus. Thisantibiotic has long been found useful for the treatment of vaginitis due to infections caused by Candida albicans and other Candida species. Prior to the present invention such infections were treated topically by means of vaginal tablets and vaginal ointments. Alternatively, such infections have been treated systemically.

Vaginal tablets are unpleasant to administer. Additionally, the antibiotic is not always released in a reproducible'and predictable manner inasmuch as its release is directly dependent upon the disintegration of the tablet in the vagina. Vaginal ointments produce a sensation of warmth when applied due to the inhibition of normal moisture evaporation. In addition, they feel greasy and tacky and have a tendency to stain the underclothing.

The present invention overcomes these disadvantages and provides a convenient means of vaginal administration in the form of a stable, non-aqueous, aerosol foam which readily breaks at body temperatures and spreads as a uniform film along the walls of the vagina. These compositions are cosmetically superior to those presently available'and provide a readily available controlled dosage directly at the situs of inflammation. The need for such formulations has long been recognized but remained unsolved primarily due to the difficulties experienced in formulating candicidin compositions.

Candicidin, encompassing a complex or a mixture of related antibiotics, is relatively unstable and undergoes degradation with a concomitant loss in activity. Thus, when exposed to the action of such physical and chemical agents as heat, light, oxygen and moisture, there is a concomitant loss in activity. Another object of this invention, therefore, is to provide anhydrous dosage forms wherein the candicidinretains its stability over long periods of time.

SUMMARY OF THE INVENTION This invention relates to novel therapeutic compositions of candicidin. More particularly, this invention relates to anhydrous, aerosol foam compositions comprising: v

a. from 0.2to.0.5% by weight of candicidin;

b. from 2 to 5% by weight of a polyoxyethylatedihigh molecular weight fatty alcohol;

c. from 0.5 to 2.0% by weight of a nonionicfsurfactant; I d. from 0.05 to 1.0% by weight of an antioxidant; e. from 5.0 to 20.0% by weight of an aerosol'propellant selected from the groupof chlorofluorohydrocarbons having a boiling point between 30C. and 30C. in a propylene glycol solvent.

DETAILED DESCRIPTION OF THE INVENTION In general the novel pressurized compositions of this invention contain the antibiotic candicidin, a foaming agent, a nonionic surfactant and a propellant contained in a vehicle of propylene glycol. These mixtures havecertain critical features both with respect to the nature and amount of the various components employed. When prepared in the manner described, these compositions retain their activity over long periods of time and produce homogenous, creamy foams that are particularlyuseful in the treatment of vaginitis.

Candicidin is an antifungal polyene antibiotic complex, fully described in U.S. Pat. No. 2,992,162. As recovered from culture filtrates the complex consists of three fractions, designated Candicidin A, B and C. The A fraction is a reddish brown powder soluble in water and is simply the sodium salt of B, a greenish powder which is water insoluble. Fraction C appears to be a degradation product which, relatively speaking, is bio-' logically inactive. Candicidin is particularly useful for topical treatment of vaginal candidiasis (moniliasis). Candicidin, however, is not very stable and formulations thereof are generally kept in dark, refrigerated,

air-tight containers to prevent loss of activity. The present invention provides formulations which retain as much as of their original antibiotic activity when kept at 4C. over a 1-year period.

Both the nature and the amount of foaming agent employed are critical with respect to the solvent vehicle utilized. Various nonionic and emulsifying agents, including the condensation products of ethylene oxide and organic acids were tried unsatisfactorily, forming either foams that were unstable or failing to produce any foams whatsoever.

I have discovered that the reaction products of ethylene oxide and the higher fatty alcohols, marketed as Polawax," produce thick, uniform, creamy foams with candicidin which are quite stable at room temperature. Furthermore, when warmed to 37C. '(body 'temperature) these foams have the surprising property of flattening out to form a fluid cream with the antibiotic. This characteristic of the foams described herein is highly desirable and can be utilized in the preparation of other vaginal foam products. The soft, cushiony foams which are produced can be safely introduced into the vagina and, after warming to body temperature, will flatten leaving a thin film of the medicament evenly distributed along the vaginal walls. The ethylene oxide and higher fatty alcohol reaction products are creamy, wax-like, nonionic, emulsifying waxes having a melting range of 485 2C., a maximum iodine value of 3.5 and a maximum saponification value of 14. The foaming agent of choice is the reaction product of ethylene oxide with stearyl alcohol. Various amounts of the foaming agent are added to the present compositions, preferably ranging from 2 to 5% by weight of the total composition. Amounts beyond 5% provide stiff foams which are too stable and which do not break upon warming. On the other hand, amounts below 2% provide loose, wet foams, which break too rapidly and which have a tendency to run.

Candicidin is insoluble in water and ethanol but is soluble in various organic solvents such as butanol, ethylene glycol, various lower molecular weight polyethylene glycols and glycerine. Butanol and ethylene glycol are unsuitable for pharmaceutical use due to their toxicity. Glycerine is non-toxic but very hygroscopic. Solutions of glycerine above cause a burning sensation with the sensitive vaginal mucous membranes due to their dehydrating nature. In addition, candicidin lacks the requisite stability in various mixtures of polyethylene glycols tested. Surprisingly, anhydrous propylene glycol was found to be effective. Propylene glycol is non-hygroscopic, non-toxic, pharmaceutically acceptable and dissolves sufficient candicidin to be therapeutically useful. Most importantly, the stability of candicidin is preserved in anhydrous propylene glycol solutions.

Candicidin is an amorphous, non'wettable, electrostatic powder. A surfactant is necessary to stabilize these compositions by preventing agglomeration and evenly dispersing the candicidin in the solvent vehicle so that solution can occur. Nonionic surfactants are utilized because of their pharmacological compatibility and their lack of irritation and toxicity. The preferred nonionic surfactants are the fatty acid partial esters of sorbitol anhydride, such as serbitan monooleate marketed as Spans, which are prepared by the esterification of sorbitan with a fatty acid such as oleic or stearic acid. Additionally, the polyoxyethylene derivatives of fatty acid partial esters of sorbitol anhydrides, marketed as Tweens, are useful. The nonionic surfactant of choice is the oleate ester of sorbitol and its anhydride, which has been copolymerized with approximately moles of ethylene oxide for each mole of sorbitol and sorbitol anhydride. This particular nonionic surfactant accelerates the dispersion of the otherwise particulate agglomerate of candicidin and aids in the desegregation and stabilization of candicidin in the aerosol container with relative ease. The amount of surfactant necessary to prevent agglomeration is not critical. Generally the surfactant is present in an amount ranging from 0.5 to 2.0% by weight of the total composition. Preferably, a concentration of about 1.0% by weight is employed.

Due to the relative ease with which candicidin undergoes oxidative degradation, it is necessary to add an antioxidant to the present compositions. The complexity of free radical oxidative processes and their sensitivity to trace amounts of impurities present critically affects both the nature and the amount of antioxidant to be used. The use of propyl gallate as an antioxidant in the propylene glycol system of the present invention has been found to be superior to all other antioxidants tried. Surprisingly, candicidin activity rapidly diminishes with propyl gallate concentrations in excess of 1%, representing the outer limits of usefulness for this antioxidant. On the other hand, a minimum or threshold amount of 0.5% of propyl gallate is found to be necessary. Maximum candicidin stability is obtained with propyl gallate at a concentration of about 0.1% by weight.

The propellant is responsible for developing the necessary pressure within the container and expelling the product once the aerosol valve is opened. The propellants used in this invention are selected from a group of fluorinated hydrocarbons known as Freons due to their excellent solubilization characteristics, their compatibility with candicidin'and their widespread use in pharmaceutical aerosols. More particularly, those chlorofluorohydrocarbons having a boiling point of from to 30C. are employed. Specifically enumerated within this group of compounds are dichlorodifluoromethane, dichlorotetrafluoroethane, monochlorodifluoroethane, difluoroethane and octafluorocyclobutane. The propellants are used individually or as mix- 4 tures. A preferred propellant mixture consists of a mixture of nine parts of dichlorotetrafluoroethane to one part of dichlorodifluoromethane. I

The amount of propellant employed varies with the actual propellants being used. ln'gene'ral, an amount less than 5.0% of propellant by weight will not produce useful results. On the other hand, an amount as high as 20% by weight of propellant can be used with propellants of low vapor pressure. As a preferred embodiment an amount of 10% by weight of a 9:1 mixture of dichlorotetrafluoroethane to dichlorodifluoromethane is employed to gassify the instant foam composition. The propellant can be added to the foam producing composition prior to its addition to the aerosol container which is then capped with a foam valve. Preferably, the foam producing composition is added to an aerosol container, capped with a foam valve and charged through the valve with the propellant on a weight basis.

The compositions of this invention are prepared by dissolving the antioxidant in a solution of the nonionic surfactant to form a nonionic surfactant solution. The candicidin is then added to the nonionic surfactant solution to form a candicidin dispersion. The polyoxyethylated high molecular weight fatty alcohol is dissolved in the propylene glycol to form a propylene glycol solution and the candicidin dispersion prepared is added to the propylene glycol solution to form an anhydrous, foam-producing composition. This composition is placed in a suitable aerosol container, capped with a foam valve and charged with the chlorofluorohydrocarbon propellant mixture.

Additional minor ingredients, such as emollients, perfumes and dyes, may be added to the compositions herein described in orderto increase their versatility and attractiveness without fundamentally departing from the nature of this invention. The non-aqueous candicidin pressurized aerosol foam compositions described herein are more particularly illustrated in con- 40 junction with the following specific examples.

EXAMPLE 1 Components Compositions Polyethylene glycol (avg m w 400) Polyoxyethylated vegetable oil Polyoxyethylated high molecular wt fatty alcohol Polyoxyethylene glycol (avg m w 400) monostearate Polyoxyethylene glycol (avg m w 400) distearate Candicidin Type of foam no form 0.04 dry stable foam 057a stable foam foam foam EXAMPLE 2 Following essentially the same procedure without the candicidin, the following example illustrates the use of various foaming agents in different solvent vehicles.

Components Compositions A B C D Mineral oil, heavy 97 95 40 Polyethylene glycol (avg m w 400) 40 97 Polyoxyethylated high molecular weight fatty alcohol 3 3 3 3 Polyoxyethylated vegetable oil 2 7 Type of foam no no no good foam when foam foam foam cool-breaks upon warming EXAMPLE 3 Following essentially the same procedure as in Example ll, the following Example illustrates the effect of a foaming agent, polyoxyethylated high molecular weight fatty alcohol, and a nonionic surfactant, the oleate ester of sorbitol and its anhydride copolymerized with ethylene oxide, with various non-aqueous solvent vehicles.

The following Example indicates the lack of'candicidin stability in a polyethylene glycol solvent foam formulation.

olyoxyethylated high molecular weight fatty alcohol foaming agent, 3 gms, is melted and dispersed in approximately 97 ml of polyethylene glycol solvent vehicle having an average molecular weight of 400. Candicidin, 0.084 gm, is dispersed in 10 gms-of the oleate ester of sorbitol and its anhydride copolymerized with ethylene oxide. The polyethylene glycol solution is added to the candicidin suspension and gm portions filled while still warm in aerosol containers equipped with a foam head. A mixture of 4 parts of dichlorotetrafluoroethane to 1 part of dichlorodifluoromethane is added via the foaming head. Initial recovery of candicidin including control values was only 50.2% and 53.2% of theory.

EXAMPLE 5 The following aerosol foam formulations illustrate the stability of candicidin using various antioxidants with a polyoxyethylated high molecular weight fatty alcohol foaming agent and a nonionic surfactant, such as the oleate ester of sorbitol and its anhydride copolymerized with ethylene oxide. Each composition was gassed with a mixture of 4 parts of dichlorotetrafluoroethane and 1 part of dichlorodifluoromethane.

Components Compositions Polyoxyethylated high molecular weight fatty alcohol 2 2 2 2 Butylated hydroxy anisole Disodium ethylenediaminetetra acetic acid Propyl gallate Oleate ester of sorbitol l l l l Candicidin Polyethylene glycol (avg m w 400) q.s. ad. Initial candicidin activity Theory) l Month at room temperature Theory) Following essentially the same procedure the following results were obtained.

Components Compositions Polyoxyethylated high molecular weight fatty alcohol 3 3 3 3 Butylated hydroxy anisole Disodium ethylenediaminetetraacetic acid Propyl gallate Oleate ester of sorbitol l l l l Candicidin Polyethylene glycol (avg m w 400) q.s. ad.

lnitial candicidin activity Theory) l Month at room temperature Theory) 1 Month at 4C. nonpressurized Theory) EXAMPLE 6 p The following Example illustrates the increased stability of candicidin in a propylene glycol vehicle. All of the samples were gassed with a mixture of 9 parts dichlorotetrafluoroethane and 1 part of dichlorodifluoromethane.

' i -continued Compositions Compositions Components A E I C D E Components A B C D E Polyoxyethyl- Potassium sorbate 0.2 ated high Candicidin 0.42 0.42 0.63 0.42 molecular Propylene glyweight fatty i col q.s. ad. 200 200 300 200 200 alcohol 3 3 3 3 3 Initial Candi- Polyoxyethylcidin assay ene sorbitan (mg/gm) 4.24 3.92 3.67 3.36 0 monooleate 1 l l 1 l 3 Months at room Propyl gallate 0.1 0.1 temperature Disod un ethyl- (mg/gm) 2.81 2.31 ene dian' ine- 3 Months at 4C. tetraacetic (mg/gm)4.52 4.06 4.27 3.23 acid 0.1 0.1 6 Months at 4C. Candicidin 0.21 0.21 0.21 0.21 (mg/gm) 4.12 4.12 3.89 Polyethylene 10% months at glycol (avg 4C. (mg/gm) 3.38 2.93 3.65 2.7 mw 400) q.s. ad. 100 100 Propylene glycol q.s. ad. 100 100 100 EXAMPLE 9 lnitial Catnqicidm The following Example illustrates variations in the ac ivity Theory) 828 7&0 951 981 propellants, nonionic surfactants and amount of candicidin used.

EXAMPLE 7 Compositions Components A B C D The following Example illustrates aerosol formula- P l h l dh, h oyoxyet yate ig tions of candicidin n a propylene glycol solvent vehicle molecular weight using various antioxidants. All formulations were stearyl alcohol 2.7 2.7 2.7 2.7 gassed with a mixture of 9 parts of dichlorotetra- 0 9 0 9 0 9 fluoroethane and 1 part of dichlorodifluoromethane. Propyl gallate 0:09 0:09 0.09 0:05

Sorbitan monooleate 0.9 candicidin 0.38 0.38 0.38 0.27

Dichlorotetra- Compositions fl th l0 10 Components A B C Dichlorotetrafluoroethane to dichloro- Polyoxyethylated high difluoromethane molecular weight (9;1) fatty alcohol 3 3 3 10 1O Polyoxyethylene sorbitan Propylene glycol monooleate 1 l l q.s. ad. 100 I00 100 100 Ethyl vanillin 0. Ascorbyl palmitate 0.1 Potassium sorbate 0.1 Candicidin 0.21 0.21 0.21 I claim; P l l l d. 0 0 l 0 s-E? lig zgz S a l0 l0 0 1. An anhydrous, aerosol foam COmPOSIUOTI useful in i a? (mg/g 3.68 3.21 3.69 the treatment of vaginitis consisting of:

cm at room temperamre (mg/gm) 3.16 205 106 a. from 0.2 to 0.5% by weight of Candicidin, f 1 Month at 4C. (mg/gm) 3.75 3.76 4.00 b. from 2 to 5% by weight of a nonionic, waxy, earn- 2 Months(at anon; t m- 2 79 2 H ing agent prepared by reacting ethylene oxide with pera ure mg gm 0 2 Months at (mg/gm) 176 26' 4,49 stearyl alcohol, having a melting range of 48 52 C., a maximum iodine value of 3.5 and a maximum saponification value of 14;

c. from 0.5 to 2.0% by weight of polyoxyethylene EXAMPLE 8 (20) sorbitan monooleate;

The following Example illustrates aerosol foam formulations of candicidin in a propylene glycol vehicle using various amounts of propyl gallate as an antioxidant. All of the compositions were gassed using a mixture of 9 parts of dichlorotetrafluoroethane and 1 part of dichlorodifluoromethane.

d. from 0.05 to 1.0% by weight of propyl gallate;

e. from 5.0 to 20.0% by weight of an aerosol propellant selected from the group of chlorofluorohydrocarbons having a boiling point between -30 C. and 30 C; and

f. propylene glycol 2. An anhydrous, aerosol foam composition useful in the treatment of vaginitis consisting of:

a. from 0.2 to 0.5% by weight of Candicidin;

b. from 2 to 5% by weight of a nonionic, waxy, foam-- ing agent prepared by reacting ethylene oxide with stearyl alcohol, having a melting range of 48 52 C., a maximum iodine value of 3.5 and a maximum saponification value of 14;

c. from 0.5 to 2.0% by weight of sorbitan monooleand 30 C.; and f. propylene glycol.

3. An anhydrous, aerosol foam composition useful in the treatment of vaginitis which consists of:

(a) Candicidin (b) a nonionic, waxy, foaming agent prepared by reacting ethylene by weight -continued oxide with stearyl alcohol, having a melting range of 48-52 C., a maximum iodine value of 3.5 and a maximum saponification value polyoxyethylene (20) sorbitan monooleate propyl gallate (e) a 9:1 mixture of dichlorotetrafluoroethane and dichlorodifluoromethane propellants (f) propylene glycol by weight UNITED STATES PATENT AND TRADEMARK OFFICE CERTIFICATE OF CORRECTIN PATENT NO.

DATED mvtmoms) 3 December 50, 1975 Norval E] lsworth Webb, Jr

Page I of 2 His certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 3, I ine 20, the patent reads "serb i tan and should read --sorbitan-;

Column 6, ines 30-31, under the Fol lowing heading:

the patent reads:

and should read:

Components "Compos i tions A B C D "sorbitol" Ill 1 1 1H --sorbito1 l 1 1 1-- Column 8, l ine 12, under the Fol lowing Heading:

the patent reads:

and should read:

UNITED sTATEs PATENT AND TRADEMARK OFFICE @E'HFICATE UF CORRECTION PATENT NO. 5,929,985

DATED INVENTOR(S) Nor-Va] December 50, 1975 E] lsworth Webb,

Jr Page 2 of It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, 1 Ines 37-58, under the Fol lowi ng head ing;

the patent reads:

and should reads A rtes r:

RUTH C. MASON Arresting Officer Components Corn ositions K B C D n II rrggr r I n Signed and Scaled this Thirty-first Day of August 1976 c. MARSHALL DANN Commissioner of Patents and Trademarks 

1. AN ANHYDROUS, AEROSOL FOAM COMPOSITION USEFUL IN THE TREATMENT OF VAGINITIS CONSISTING OF: A. FROM 0.2 TO 0.5% BY WEIGHT OF CANDICIDIN; B. FROM 2 TO 5% BY WEIGHT OF A NONIONIC, WAXY, FOAMING AGENT PREPARED BY REACTING ETHYLENE OXIDE WITH STEARYL ALCOHOL, HAVING A MELTING RANGE OF 48*-52*C., A MAXIMUM IODINE VALUE OF 3.5 AND A MAXIMUM SAPONIFICATION VALUE OF 14; C. FROM 0.5 TO 2.0% BY WEIGHT OF POLYOXYETHYLENE (20) SORBITAN MONOOLEATE; D. FROM 0.05 TO 1.0% BY WEIGHT OF PROPYL GALLATE; E. FROM 5.0 TO 20.0% BY WEIGHT OF AN AEROSOL PROPELLANT SELECTED FROM THE GROUP OF CHLOROFLUOROHYDROCARBONS HAVING A BOILING POINT BETWEEN -30*C. AND 30*C; AND F. PROPYLENE GLYCOL.
 2. An anhydrous, aerosol foam composition useful in the treatment of vaginitis consisting of: a. from 0.2 to 0.5% by weight of Candicidin; b. from 2 to 5% by weight of a nonionic, waxy, foaming agent prepared by reacting ethylene oxide with stearyl alcohol, having a melting range of 48*-52* C., a maximum iodine value of 3.5 and a maximum saponification value of 14; c. from 0.5 to 2.0% by weight of sorbitan monooleate; d. from 0.05 to 1.0% by weight of propyl gallate; e. from 5.0 to 20.0% by weight of an aerosol propellant selected from the group of chlorofluorohydrocarbons having a boiling point between -30* C. and 30* C.; and f. propylene glycol.
 3. An anhydrous, aerosol foam composition useful in the treatment of vaginitis which consists of: 